1 files changed, 63 insertions, 0 deletions

diff --git a/drivers/iio/trigger/stm32-timer-trigger.c b/drivers/iio/trigger/stm32-timer-trigger.c
index 32e1249f2b91..37545a8a02b7 100644
--- a/drivers/iio/trigger/stm32-timer-trigger.c
+++ b/drivers/iio/trigger/stm32-timer-trigger.c
@@ -75,6 +75,15 @@ static const void *stm32h7_valids_table[][MAX_VALIDS] = {
 	{ }, /* timer 17 */
 };
 
+struct stm32_timer_trigger_regs {
+	u32 cr1;
+	u32 cr2;
+	u32 psc;
+	u32 arr;
+	u32 cnt;
+	u32 smcr;
+};
+
 struct stm32_timer_trigger {
 	struct device *dev;
 	struct regmap *regmap;
@@ -86,6 +95,7 @@ struct stm32_timer_trigger {
 	bool has_trgo2;
 	struct mutex lock; /* concurrent sysfs configuration */
 	struct list_head tr_list;
+	struct stm32_timer_trigger_regs bak;
 };
 
 struct stm32_timer_trigger_cfg {
@@ -812,6 +822,58 @@ static int stm32_timer_trigger_remove(struct platform_device *pdev)
 	return 0;
 }
 
+static int __maybe_unused stm32_timer_trigger_suspend(struct device *dev)
+{
+	struct stm32_timer_trigger *priv = dev_get_drvdata(dev);
+
+	/* Only take care of enabled timer: don't disturb other MFD child */
+	if (priv->enabled) {
+		/* Backup registers that may get lost in low power mode */
+		regmap_read(priv->regmap, TIM_CR1, &priv->bak.cr1);
+		regmap_read(priv->regmap, TIM_CR2, &priv->bak.cr2);
+		regmap_read(priv->regmap, TIM_PSC, &priv->bak.psc);
+		regmap_read(priv->regmap, TIM_ARR, &priv->bak.arr);
+		regmap_read(priv->regmap, TIM_CNT, &priv->bak.cnt);
+		regmap_read(priv->regmap, TIM_SMCR, &priv->bak.smcr);
+
+		/* Disable the timer */
+		regmap_update_bits(priv->regmap, TIM_CR1, TIM_CR1_CEN, 0);
+		clk_disable(priv->clk);
+	}
+
+	return 0;
+}
+
+static int __maybe_unused stm32_timer_trigger_resume(struct device *dev)
+{
+	struct stm32_timer_trigger *priv = dev_get_drvdata(dev);
+	int ret;
+
+	if (priv->enabled) {
+		ret = clk_enable(priv->clk);
+		if (ret)
+			return ret;
+
+		/* restore master/slave modes */
+		regmap_write(priv->regmap, TIM_SMCR, priv->bak.smcr);
+		regmap_write(priv->regmap, TIM_CR2, priv->bak.cr2);
+
+		/* restore sampling_frequency (trgo / trgo2 triggers) */
+		regmap_write(priv->regmap, TIM_PSC, priv->bak.psc);
+		regmap_write(priv->regmap, TIM_ARR, priv->bak.arr);
+		regmap_write(priv->regmap, TIM_CNT, priv->bak.cnt);
+
+		/* Also re-enables the timer */
+		regmap_write(priv->regmap, TIM_CR1, priv->bak.cr1);
+	}
+
+	return 0;
+}
+
+static SIMPLE_DEV_PM_OPS(stm32_timer_trigger_pm_ops,
+			 stm32_timer_trigger_suspend,
+			 stm32_timer_trigger_resume);
+
 static const struct stm32_timer_trigger_cfg stm32_timer_trg_cfg = {
 	.valids_table = valids_table,
 	.num_valids_table = ARRAY_SIZE(valids_table),
@@ -840,6 +902,7 @@ static struct platform_driver stm32_timer_trigger_driver = {
 	.driver = {
 		.name = "stm32-timer-trigger",
 		.of_match_table = stm32_trig_of_match,
+		.pm = &stm32_timer_trigger_pm_ops,
 	},
 };
 module_platform_driver(stm32_timer_trigger_driver);